Best place to sell a digital download game code?

I recently bought the Madden 2015 Xbox One bundle but am not really into sports games and have no intention of playing it. What would be the best way of selling the digital download code to someone who would play the game? Thanks

On this forum or via eBay auction. Cheap Ass Gamer has a trading/selling forum. Sorry if you knew this already.

Good luck and sorry I wasn't of more help.